'\" te
.\"  Copyright (c) 2003, Sun Microsystems, Inc.,  All Rights Reserved
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.TH LDI_PROP_EXISTS 9F "Jun 3, 2003"
.SH NAME
ldi_prop_exists \- Check for the existence of a property
.SH SYNOPSIS
.nf
#include <sys/sunldi.h>

\fBint\fR \fBldi_prop_exists\fR(\fBldi_handle_t\fR \fIlh\fR, \fBuint_t\fR \fIflags\fR, \fBchar *\fR\fIname\fR);
.fi

.SH INTERFACE LEVEL
illumos DDI specific (illumos DDI)
.SH PARAMETERS
.ne 2
.na
\fB\fIlh\fR\fR
.ad
.RS 9n
Layered handle.
.RE

.sp
.ne 2
.na
\fB\fIflags\fR\fR
.ad
.RS 9n
Possible flag values are some combination of:
.RE

.sp
.ne 2
.na
\fBLDI_DEV_T_ANY\fR
.ad
.RS 21n
Match the lookup request independent of the actual dev_t value that was used
when the property was created. The flag indicates any dev_t value (including
DDI_DEV_T_NONE)  associated with a possible property match satisfies the
matching criteria.
.RE

.sp
.ne 2
.na
\fBDDI_PROP_DONTPASS\fR
.ad
.RS 21n
Do not pass request to parent device information node if the property  is not
found.
.RE

.sp
.ne 2
.na
\fBDDI_PROP_NOTPROM\fR
.ad
.RS 21n
Do not look at PROM properties  (ignored  on platforms that do not support PROM
properties).
.RE

.sp
.ne 2
.na
\fB\fIname\fR\fR
.ad
.RS 21n
String containing the name of the property.
.RE

.SH DESCRIPTION
\fBldi_prop_exists()\fR checks for the existence of a property associated with
a device represented by the layered driver handle, regardless of the property
value data type.
.sp
.LP
Properties are searched for based on the dip and dev_t values associated with
the layered handle, and the property name. This  association is handled by the
layered driver infrastructure on behalf of the consumers of
\fBldi_prop_exists()\fR.
.sp
.LP
The property search order is as follows:
.RS +4
.TP
1.
Search software-properties created by the driver.
.RE
.RS +4
.TP
2.
Search the software properties created by the system (or nexus nodes in the
device info tree).
.RE
.RS +4
.TP
3.
Search the driver global properties list.
.RE
.RS +4
.TP
4.
If DDI_PROP_NOTPROM is not set, search the PROM properties (if they exist).
.RE
.RS +4
.TP
5.
If DDI_PROP_DONTPASS is not set, pass this request to the parent device
information node of the device  represented by the layered handle.
.RE
.RS +4
.TP
6.
Return \fB0\fR if not found and \fB1\fR if found.
.RE
.sp
.LP
Typically, the specific dev_t value associated with the device represented by
the layered handle (ldi_handle_t) is used as a part of the property match
criteria. This association is handled by the layered driver infrastructure on
behalf of the consumers of the ldi property look up functions.
.sp
.LP
However, if the LDI_DEV_T_ANY flag is used, the ldi property lookup functions
will match the request regardless of the dev_t value associated with the
property at the time of its creation.  If a property was created with a dev_t
set to DDI_DEV_T_NONE, the only way to look up this property is with the
LDI_DEV_T_ANY flag.  PROM properties are always created with a dev_t set to
DDI_DEV_T_NONE.
.sp
.LP
name must always be set to the name of the property being looked up.
.SH RETURN VALUES
\fBldi_prop_exists()\fR returns \fB1\fR if the property exists and \fB0\fR
otherwise.
.SH CONTEXT
This function may be called from user or kernel context.
.SH EXAMPLE
.in +2
.nf
The following example demonstrates the use of ldi_prop_exists().

     /* Determine the existence of the "interrupts" property */
       ldi_prop_exists(lh, LDI_DEV_T_ANY|DDI_PROP_NOTPROM, "interrupts");
.fi
.in -2

.SH SEE ALSO
\fBddi_prop_exists(9F)\fR
.sp
.LP
\fIWriting Device Drivers\fR
